Autonomous or self-guided obstacle avoidance is an important feature of mobile platforms. Techniques for enabling a mobile platform to detect potential obstacles in its spatial environment include, for example, ultrasound, time-of-flight, and other methods. Individual methods, however, each have certain drawbacks that render them non-ideal for self-guided obstacle avoidance. For example, ultrasound-based obstacle detection has limited detection range (commonly less than five meters) as well as limited sensitivity to small objects. Hence, ultrasound-based devices are insufficient for use in obstacle avoidance of fast-moving objects (for example, objects moving faster than 10 meters per second), since the limited detection range gives insufficient warning for the mobile platform or vehicle to decelerate and avoid the obstacle.
Time-of-flight (ToF) sensing, an alternative technique, can acquire obstacle distances based on a travel time of emitted light to and from the obstacle. Advantages of time-of-flight sensing include long detection range and high resolution. But time-of-flight sensing has certain drawbacks for mobile platform obstacle detection. For example, strong ambient light may result in a low signal-to-noise ratio for time-of-flight sensors. Furthermore, a time-of-flight signal can vary based on reflective properties of the object imaged, particularly for mirror-like objects such as glass or water surfaces.
In view of the foregoing, there is a need for systems and methods for mobile platform operation for obstacle avoidance that overcome disadvantages of individual distance detection methods.
It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are generally represented by like reference numerals for illustrative purposes throughout the figures. It also should be noted that the figures are only intended to facilitate the description of the preferred embodiments. The figures do not illustrate every aspect of the described embodiments and do not limit the scope of the present disclosure.